(AKA 'Summer Eczema', 'Queensland Itch', 'Summer Seasonal Recurrent
This is one of the seasonal problems that besets some unfortunate horse owners
at this time of the year. It affects all types of horses but is more likely
to be found in the pony and cob breeds, Icelandic horses too seem particularly
prone. It is also thought to be hereditary and for this reason it is unadvisable
to breed from an animal with this complaint.
The cause of Sweet itch is a midge called Culicoides pulicaris.
These minute flies breed in wet, muddy areas in marshes, along the esturies
of rivers and around lakes or in wet, decaying vegetable material, e.g woodlands.
These midges are active, usually in swarms, principally in the early morning
and late afternoon, although if it is cool and humid with no wind they may
remain active throughout the day. A small proportion of horses, usually but
not always, those that are outdoors all the time develop a hypersensitive
reaction to a protein in the saliva of the female midge. These midges are
active between the months of April to late October, but tend to be more prevelent
during the months of May, June and September.
The midges that cause sweet itch usually feed along the dorsal surface of
the horse (forehead, base of mane, withers, back, rump, base of tail) and it
is in these areas that symptoms are first seen. These can vary from occasional
rubbing of the mane and tail to complete loss of the mane and upper tail hairs.
The itching can become so severe that the horse may rub itself for prolonged
periods against trees and posts, often developing open sores on the head, neck,
withers and dock. The skin often becomes scurfy and itchy along the whole length
of their back. In time the repeated rubbing causes the characteristic thickening
and ridging of the skin at the base of the mane and tail. Sometimes secondary
bacterial infections can develop.
This is very much the case of 'prevention is better than cure'. So if you know
your animal is prone to this then you should aim to prevent the symptoms by careful
management rather than waiting for them to develop.
- move affected animals out of marshy fields and away from rivers,lakes and
- stable then from at least 4 pm until 8 am during the summer months
- use a summer sheet, preferably with complete neck and tail covers to protect
the base of the mane and tail. Specially manufactured anti-midge rugs and
'pyjamas' are now available.
- use a fly repellant twice daily or a long-acting fly repellant every few
- the addition of garlic to the diet can reputedly help although this has
not been scientifically proven
- magnesium rich mineral blocks have also been reported as causing a marked
improvement in some animals
For severely affected animals the above precautions should still be undertaken,
- the application of soothing lotions to the skin such as benzyl benzoate
- use of a coal tar soap or shampoo with careful rinsing every week or so
can help to remove the scurf and scabs
- where skin is very sore a corticosteroid cream may be required to help
reduce inflammation and aid the healing process
- long acting corticosteroid injections can sometimes be given to reduce
the irritation, but this drug has many side-effects one of which is to induce
laminitis in some animals, so for this reason great care should be taken
and this should be discussed with your veterinary surgeon
The good news is that Sweet Itch only affects a small minority of animals
and is not an infection that can spread from horse to horse. Unfortunately
once a horse or pony has become allergic to these insects it will always remain
so. Sweet Itch can be both debilitating and unsightly. It prevents the animal
from being used for showing and its sores may prevent or limit its being ridden
in the summer. Sweet Itch can become costly in time, effort and money and the
torment and misery endured can make some ponies bad-tempered and unreliable.
Very often many of these animals are sold during the winter months when the
condition is not present and the problem is passed on to another unsuspecting
owner. Purchasers should always be warned about animals with this condition
as they require special attention and should therefore go to experienced homes
with suitable facilities, otherwise it is best to steer clear of any animal
suspected of having Sweet Itch.
"..try tieing 'cow fly tags' on each side of the headcollar, apparently farmers
use these tags to help keep the flies off their cows and they cost about £2.50
each. (The animal's body gets coated in the insecticide by the swishing of their
heads and tails) Whether this really works is another matter - it's very much
a case of trial and error..."